Biomechanics in Sports and Physical Therapy

Study Notes

Mechanics is the branch of physics dealing with the behavior of physical bodies subjected to forces (kinetics) or displacements (kinematics)
Classic mechanics deals with particles at rest or moving at velocity less than the speed of light
Biomechanics is a science applying the laws of mechanics to biological systems
It uses mathematics, physics, engineering, computer science and biology and describes biological materials and their responses to forces and torques

Biomechanics analyses bone, soft tissue, artificial structures, and musculoskeletal systems
It investigates implant design and testing, including metal fatigue
It models human movement and describes the forces causing it
It studies the interaction of man-made materials with the musculoskeletal system

Biomechanics in sports and physical therapy improves performance and identifies areas requiring improvement
Measurements provide objective evaluation
The analysis of injuries, their mechanisms, and interventions is facilitated
It helps understand biological systems

Ergonomics teaches workers proper posture and techniques to avoid injuries
It designs safer workplaces and tasks
It addresses overuse injuries, which are related to repetition, not force levels

Statics examines systems not undergoing acceleration but in equilibrium
Dynamics studies systems in motion due to unbalanced forces causing acceleration.
Pseudo-static analysis assumes that particular moments can be viewed as static equilibriums

Kinematics describes movement without considering forces
Kinetics studies the forces and momentum acting during movement
Kinematics evaluates position, velocity, and acceleration (linear or angular)
Kinetics considers force and momentum (linear or angular) and interrelationships between them

Kinematics describes the motion of a body irrespective of the forces causing it.
Kinetics describes the forces and interactions affecting a body's movement over time
Quantitative analysis involves numerical evaluation of movement
Qualitative analysis evaluates movement based on observation, not measurements

Reverse anatomy glenohumeral joint replacement is used for rotator cuff arthropathy
Joint centers are offset to provide increased lever arms for the deltoid muscle function

Joints usually have one or more degrees of freedom
Different types of joints, such as hinge, ball-and-socket, and gliding joints, have distinct movement properties

ROM is determined by the structure of a joint, muscle extensibility, and tendon and ligament properties.
Bone shape, joint stiffness, and soft tissue elasticity all influence ROM.
ROM is quantified in degrees

Gait is a complex movement pattern
Different kinetic data analysis techniques assess, via internal/external measurements, forces acting on the body

Real-time measurement of internal and external forces within the body is used to inform clinicians.
Kinetic data includes force, moment, momentum

Net force, applied at or aligned with a body's center of mass, creates linear motion in the direction of the force.
Force equals mass multiplied by acceleration (F=ma)
A moment or torque occurs when a net force acts off the center of mass.

Kinematic equations describe the relationships between distance, velocity, acceleration, and time
These calculations can be utilized in simulations, research, and other applications that involve movement analysis